Corn popping machine



1953 J. LINDSTROM ET AL ,6

CORN POFPING MACHINE Filed Nov. 15, 1947 10 Sheets-Sheet l INYENTORSJo/m Zmaszram & BIY Burgess C. Case ATTORNEY 1953 J. LINDSTROM ET AL2,657,627

CORN POPPING MACHINE Filed NOV. 15, 1947 10 Sheets-Sheet 2 .fligi 2INVENTORS John Linda from & BY Burg/es: C Case NW ATTO RNEY Nov. 3, 1953J. LINDSTROM ET AL 2,657,627

CORN POPPING MACHINE Filed Nov. 15, 1947 10 Sheets-Sheet 3 BY Burgess CCase ATTORNEY 1953 J. LINDSTROM ETAL 2,657,627

CORN POPPING MACHINE Filed Nov. 15, 1947 10 Sheets-Sheet 4 Fig 24 BYBurgess C Case M. ATTORNEY Nov. 3, 1953 J. LINDSTROM ET AL 2,657,627

CORN POPPING MACHINE Filed Nov. 15, 1947 10 Sheets-Sheet 5 INVENTORSJohn L in dszfrom&' B Burgess C Case ATTORN EY Nov. 3, 1953 J. LINDSTROMET AL 2,557,627

CORN POPPING MACHINE Filed Nov. 15, 1947 10 Sheets-Sheet 6 INVENTORSJohn Zizms from & BY Burgess C Case ATTORNEY 1953 J. LINDSTROM ET AL2,657,627

CORN POPPING MACHINE Filed Nov. 15, 1947 10 SheetsSheet 7 INVENTO R 5.93 Jofinlinaszfrom 4 BY Burgess C Case @9 g. 13

ATTORN EY Nov. 3, 1953 Filed Nov. 15, 1947 J. LINDSTROM ET AL 2,657,627

CORN POPPING MACHINE 10 Sheets-Sheet 8 O Q x g 1;

a s l\ Bl Q .J K s 2 0 g") INVENTORS Jo/m Zindsirom 45 BY Burgess C CaseATTORN EY Nov. 3, 1953 J. LINDSTROM ET AL 2,657,627

CORN POPPING MACHINE Filed Nov. 15, 1947 10 Sheets-Sheet 9 FZUURESCENT[AMP LAMP 54.41.1457

THEE/M05 771 7 omv Hl-ATER E9: INVENTORS J29}??? Lindsirom 4 svfiurg essC Case WWATTORNEY Patented Nov. 3, 1953 CORN POPPING MACHINE JohnLindstrom, Montclair, and Burgess C. Case, Plainfield, N. J.

Application November 15, 1947, Serial No. '7 86,190

4 Claims.

This invention relates in general to improvements in the constructionand mode of operation of corn popping machines, and. more particularly,of coin-operated automatic corn popping machines, which, on theinsertion of a coin with the machine in its normal operating condition,will pass through a cycle of operations beginning with the loading of acorn cup with raw corn, the movement of the loaded cup into a dumpingposition relative to a perforated popping basket reciprocating in a bathof hot cooking oil, the return of the cup to its loading position, thepopping of the raw corn for a predetermined time, and the lifting of thereciprocating popping basket out of the bath to a position where thepopped corn is discharged through a chute into a bag, such as disclosedin Case U. S. Patent No. 2,216,805.

The general object of. the present invention is the provision of a cornpopping machine of the character described which is furthercharacterized by its ease and relatively low cost of manufacture,simplicity of operation, and facility for cleaning and repair. A morespecific object is the provision of a machine of the character describedhaving a minimum number of parts and in which substantially all of theparts are made of stampin s, and die castings. Another specific objectis the provision of a raw corn tank for such machines having an improvedbottom construction facilitating the discharge of raw corn. Anotherpecific object is the provision of a raw corn cup for such machineshaving a combined bottom support and counterbalance capable ofadjustment for varying the volumetric capacity of the cup. Anotherspecific object is the provision of a popping basket for such machineshaving a special door construction for preventing dripping of cookingoil therefrom. Another specific object is the provision of an improvedcooking oil pan construction requiring only a relatively low volume ofcooking oil while providing a relatively high rate of heat transmission.Another specific object is the provision of an improved float controlmechanism providing an accurate control of the cooking oil level in thepan at all times and actuating the coin rejecting mechanism whenever theoil level falls below a predetermined value. Another specific object isthe provision of a process of and control mechanism for maintaining thecorn popping period and oil temperature within a critical time andtemperature range respectively. Another specific object is the provisionof electrically operated control mechanism for actuating the coin mecha-2 nism to reject all coins during the initial period of heating thecooking oil and to prevent the float control mechanism from beingactuated during that period.

The various features of novelty which charwcterize the inventionarepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,its operating advantages and specific objects obtained by its use,reference should be had to the accompanying drawings and descriptivematter in which is illustrated and described a preferred embodiment ofthe invention.

Of the drawings:

Fig. 1 is a front elevation of a corn popping machine constructed inaccordance with the invention, the front door being open to show theinternal arrangement;

Fig. 2 is a sectional elevation of the op /rating mechanism taken on theline 2-2" of Fig. 3';

Fig. 2 is a plan view of the pan filler block;

Fig. 3 is a rear view of the operating mechanism;

Fig. 4 is a perspective of a portion of the operating mechanism;

Fig. 5 is a vertical section of the drive mechanism taken on the line5-5 of Fig. 6;

Figs. 6 and 'I' are plan and side views respectively of the drivemechanism shown in Fig. 5

Figs. 8, 9 and 10 are elevations of the loading, agitator, and dumpingcams respectively;

Figs. 11, 11 and 12 are side, fragmentary bottom plan, and bottom viewsrespectively of the raw corn tank;

Fig. 13 is a sectional elevation of the corn cup;

Figs. 14, 1'5 and 16 are plan, elevation and front views respectively ofthe popping basket;

Fig; 16 is an enlarged sectional elevation of the popping basket door;

Fig. 17 is an elevation, partly in section, of the cooking oil tankassembly;

Figs. 18, 19 and 2 0 are elevation, plan and end views respectively ofthe float control mechanism;

Fig. 21 is a sectional elevation of the motor switch assembly;

Fig. 22 is a schematic wiring diagram of the machine;

Fig. 23 is a diagrammatic view showing the sequence of the timingrelays; and

Fig. 24 is an end view of the corn chute.

The automatic corn-operated corn popping machine illustrated in the drawngs is ccntained by a cabinet 30 of substantially rectangular horizontal and vertical cross-section having a front door 3| containing anopening 32 for the insertion of a bag by the customer into an open-facedshell forming a bag receiver compartment 33 and supported on a chassis34 removably mounted on brackets secured to the side walls of thecabinet. A door slot 35 provides access to a bag dispenser 36 on thechassis 34. A tapering corn chute 3'! opens through the top of thecompartment 33. The upper part of the cabinet contains a raw corn tank38 and a cooking 0r seasoning oil tank 39.

As shown in Figs. 2 and 3, in accordance with the invention the tanks 38and 39 are adjustable mounted on the side walls of the cabinet andchassis to facilitate the proper positioning of the tanks relative tothe operating mechanism. The corn tank 38, for example, has an upperangle bracket 48 on its outer side arranged to fit over an oppositelyarranged angle bracket 4| A on the cabinet side wall. The lower end ofthe tank carries a pair of flattened U-shaped brackets 42 secured inposition by nuts 45 on threaded studs 43 on the cabinet projectingthrough vertical bracket slots 44. Adjusting screws 46 on flanges 41projecting from the cabinet wall abut the lower flanges of the brackets42 to position the tank at the desired level. A vertically adjustablestandard 48 mounted on the chassis has its upper end shaped to form ashelf on which the lower inner edge of the tank 38 rests. A similarsupporting arrangement is used for the cooking oil tank 39.

The tanks 38 and 39 have removable tops, to which access is had throughthe hinged top 49 of the cabinet. The corn tank, as shown in Figs. 11,l1 and 12, has a special bottom construction for facilitating thedischarge of the corn kernels. The tank bottom 58 is flat with an ovatecorn discharge opening 5| adjacent its inner end. An inclined baffle 52extends downwardly from the outer wall of the tank to form a taperingfalse bottom and is bent and cut away to contact with the bottom platearound the opening 5|, the edges of the cut out portion 53 beingslightly spaced from the opening to form a narrow ledge 54, as shown inFig. 11 which causes the kernels to tumble in passing to the dischargeopening.

The discharge of corn through the opening 5| is controlled by theposition of a shut-off slide 56 mounted in guide plates 51 on the tankbottom and spring loaded by a pair of tension spring; 58 extendingbetween the outer flanged end of the slide 56 and the inner flanged endsof the plates 51, as shown in Fig. 12. The inner end of the slidecarries a plate 59 on its underside having a depending curved lip 60adapted to contact with a corn cup 88 hereinafter described. An agitatorfinger 62 detachably mounted on the inner end of the slide extendsupwardly through the tank opening 5| to prevent the corn in the tankfrom bridging adjacent the discharge opening. The inward movement of theslide is limited by contact of the outer flanged end of the slide withthe outer ends of the guide plates 51, as shown in Fig. 12. A dependingflange 63 on the slide is contacted to move the slide outwardly againstthe springs 58 as the corn cup is moved into its loading position. Thefinger 62 fits into the smaller end of the opening 5| in the retractedposition of the slide.

The driving mechanism of the machine comprises a constant speedcapacitor type electric motor 65 driving a shaft 66 carrying a worm 81meshing with a worm. wheel 68 on a shaft 69.

The shaft 88 carries a worm l0 meshing with a worm wheel H on a shaft12. A popping basket reciprocating or agitator cam 14, shown in Fig. 9,is mounted on the shaft 69. The shaft 12 has a loading cam 15, shown inFig. 8, and a dumping cam 16, shown in Fig. 10, mounted on the rear andfront ends thereof respectively.

The loading cam I5 is of the internal type and has a cam groove TI inits rear face in which rides a cam roller 18 carried by a plate 19pivoted on a pivot shaft 88. The cam groove is shaped with a single peakor lobe 8| which causes the roller 18 and plate to oscillate about theaxis of shaft to move a vertical arm 82, bolted to the outer edgeportion of the plate 19, between corn loading and dumping positions. Thearm passes through a slot in a guide plate 83. A horizontally arrangedfinger 84 is secured on the upper end of the arm 82, with its outersection B4 curved upwardly as shown in Fig. 3 to abut the inner face ofthe flange 63 and its inner section 84 rearwardly offset and arranged toabut an upwardly curved tongue 85 on the cover 85 of a popping basket94. The arm 82 also carries an L-shaped bracket 86, the flexiblevertical leg of which is slightly spaced from the arm and terminates ina yoke 81, in which the corn cup 88 is pivotally mounted.

The corn cup 88, as shown in Fig. 13, is formed by a cylindricalopen-ended shell having openings 89 for the yoke pivot pins. At thestart of the operating cycle, the slide 56 is retracted and the cup inits loading position shown in Fig. 3 where it fills by gravity throughthe corn tank hole 5|. As the loading cam actuates the cup arm 82 tomove the loaded cup from under the tank, the shut-off slide follows tocover the bottom of the hole 5| and prevent any corn from spillingthrough the hole. As shown in Figs. 3 and 11, the hole 5| is notcompletely closed in the inner position of the slide. The corn cup isconstructed so that its center of gravity when fully loaded will be invertical alignment with its pivot axis, and when empty will be outwardlyoffset, so that the cup will be tilted with its upper end towards thecorn tank during its return movement. For this purpose and to provide avolumetric capacity adjustment, a false cup bottom 90 is stepped andadjustably supported by a bracket 9| held in position by a stud 92extending through a vertical slot 93 in the shell. The bracket and studprovide the necessary counterbalance to tilt the cup when empty. Thetilt of the cup facilitates its passage below the corn tank lower inneredge when returning to its loading position, which is desirable as theclearance between the tank and cup to enable free travel of the cup isnormally only g g". The normal position of the corn cup relative to thetank is adjustable by loosening the bolts 82 holding the arm 82 on theplate 19 and shifting the location of the lower bolt in an arcuate slot82 in the plate.

The corn popping basket 84, as shown in Figs. 14-16, is of substantiallyrectangular cross-section with imperforate side and rear walls, aperforate stepped bottom 95, a front discharge door 96 hinged at itslower end, and a top 9? closed except for a hinged cover 85. A hingespring 93 maintains the cover closed until the finger 84 rides on thetongue 85 to raise the cover to allow the corn cup to dump. Dumping iseffected by the corn cup engaging a snubbing post I88 which isvertically adjustable on the outer side of the basket midway of itslength and formed by a plate bent as shown in Fig. 16 to have anoutwardly acsacz r inclined section {00' an inwardly inclined sectionMG, and 'a downwardly and inwardly extending sect-ion -IIHI As shown,the section IDS is inclined approximately '15", section is 27, andsection I5?! is from the vertical. The loaded corn cup is movedlaterally until its lower edge contacts with the post section Icilcausing the cup to tilt about the pivot axis, and the continued movementof the arm J82 flips the pivoted cup over the top of the postsufliciently to discharge all of the corn therein down the surface ofthe post section 1 58 into the popping basket.

'The stepped perforated popping basket bottom 95 facilitates theentrance and drainage of cooking oil during operation. The basketdischarge door 96, as shown in Fig. l c has a 'two-part-construction toeliminate any dripping of oil therefrom when in the corn dischargingposition, consisting of a solid outer plate Hi2 hing-ed at its loweredge on a hinge pin Hi3 on the basket and a-rcuate side wings 4'84 toconfine the popped corn when discharging. The side edges of the plateforwardly of the wings are bent inwardly to provi'de guide flanges N fora perforated inner plate I5 5 which is also hinged on the pin int and extends in Slightly spaced relation to the plate m2. The spacing ismaintained and the upper of the interplate space closed by bending overthe discharge edge :of the plate I35 to contact with the plate I92.along its bent edge is left solid to form in effect a shallow closedpocket along the discharge edge of the door.

The popping basket is reciprocably supported as hereinafter described ina rectangular pan 1.10 for holding the cooking oil, as shown in Figs. 2and 4. A forwardly curved leaf spring I39 removably mounted on the frontside of the pan continuously presses against the basket door 95 andholds the door in its closed position while the basket is reciprocatedwithin the pan. The spring curvature permits the basket to be returnedto its normal position in the pan without interference. The rear sectionof the pan is formed as a control float chamber IN by a verticaltransverse baffle H2 having openings l I3 therein for the passage of theoil. The amount of oil required for a predetermined oil level in the panI II} is substantially reduced by the position- .ing of a solid fillerblock I I5 of high thermal conductivity metal, such as aluminum, in thebasket compartment. The lock has a longitudinal recess lit in which athermal bulb Ill is removably secured by suitable clips. The block iscut away "along its bottom and rear sides to permit the flow of cookingoil to and from the float chamber Hi and to facilitate removal of theblock. The thermal conductivity and heat storage capacity of the fillerblock is substantially equivalent to that of a similar volume of cookingoil, whereby the volume of oil in the pan is sub stantially reducedwithout affecting the level of oil in the popping basket, butcorrespondingly reducing the cleaning and odor eliminating problemsencountered in operation.

The cooking oil pan is heated by a radiation type electric heater I29consisting of a plurality of serially connected heating coils I2I havingin sulated supports from a surrounding rectangular frame I22 below thepan and mounted on a base plate I23 formed of artificial stone, whichserves to reflect most of the heat radiated by the heating coils, thussubstantially minimizing the rate of crystallization of the heatingcoils. The pen I In, heater I20, andbase plate I23 are supported Theportion Hit of the plate I'i ii 6 in a rectangular metal oven I25. Theelectric current supply to the heater is provided through terminals I26and leads Ill.

The popping basket is continuously horizontally reciprocated throughoutthe operating cycle. This movement is effected by a lever 130 having afixed pivoot 129 at its lower end and carrying a cam roller is! adjacentthereto positioned in a groove I32 in the outer face of the agitator cam:4 which is formed as shown in Fig. 9 with symmetrically spaced pointsI33, over which as the cam rotates at a constant speed, the roller onthe lever is moved forwardly rearwardly. This motion is transmitted tothe basket by a linkage consisting of a horizontal link I34 connectingthe lever I'M to a yoke I235 pivoted on a pair of arms I35 projectingfrom the sides of the oven I25 and with the upper ends of the yokepivotally connected to a pair of projecting horizontal support arms I3?!secured to the sides of the basket and holding the basket at the desiredlevel in the pan 1.10.

Near the end of the operating cycle the popping basket is lifted out ofthe pan H5 order to dump the finished corn into the delivery chute 52!.For this purpose the dumping cam 16 shown in Fig. 1 0 is synchronizedwith the loading cam 15 so that the cam 3'5 depresses a cam roller I41carried by a lever I 52 pivoted on the shaft at the end of the desiredpopping period. The free end of the lever is connected to a yoke I 43pivotally connected to the front ends of the basket arms it? through anadjustable link M4 having a ball and socket joint I45. The yoke arms I35and I43 are detachably mounted on pivot pins on the basket arms :I3I tofacilitate the removal of the basket for cleaning. The dumping height ofthe basket can be raised or lowered by this screw adjustment on the balland socket joint. The loading and dumping cams are timed to allow adelay of several seconds between the dumping of the popped corn and theloading of fresh corn into the basket, to compensate for possibleoverride of the motor after the current supply is out off.

The cooking or seasoning oil reservoir tank 39 is designed to use anystandard type of cooking compound of the liquid, solid or hydrogenatedtype, a cocoanut base oil being preferred however having a meltingtemperature of approximately 76 F. To insure an adequate supply ofliquified oil, an electrically operated immersion heater I50 isinstalled in the bottom of the tank. This heater maintains thetemperature of any solid cooking compound above its liquifying point. Ascreened standpipe I5I in the tank maintains a minimum level of oilabove the heater I 50 to protect the heater from overheating. The oilflows by gravity from the standpipe I5I, the bottom of which is closedby a cleanout plug I52, to

a spring loaded solenoid operated control valve I53 and discharge pipeI54. The lower end of the pipe I54 is flattened, as shown in Fig. 1'7,and positioned within and along one side of the pan float chamber III.

The oil level in the float chamber II I and thereby also in the basketsection of the pan is controlled by a pancake type elongated float I55carried on a bracket I56, the outer end of which is pivotally mounted onan external standard I51. The bracket carries one end of a flat springswitch contact I 58 which is moved by the rise and fall of the floataway and towards respectively a stationary spring contact I59. The ratioof oil rise to switch movement is approximately 2:1.

7 Closing of the contacts I58, I59 is arranged to energize the solenoidvalve I53 and allow a gravity flow of oil to the pan H0. The rate offlow of oil through the valve is made approximately the same as the oilconsumption during the popping cycle. The spring contacts I58, I59 arecarried on a bracket I69 which is vertically adjustable on the standardI51 by an adjusting screw IBI movable in a vertical slot I62 on thestandard. The standard carries a zero marking, while the bracket I60 hasscale graduations thereon to standardize the adjustment thereofeffected. Lowering of the switch bracket in the standard will lower thecooking oil level maintained and vice versa. Too high an oil level is a1 waste of cooking oil, while too low a level will result in unpopped orincompletely popped corn. The desired level is initially determined whenthe oil is at approximately operating temperature.

As indicated in Fig. 22, the solenoid is in the same circuit as the coinmechanism and float switch.

The corn chute 31 extends through the upper side of the shell 33 formingthe bag receiver compartment with its upper part supported from the ovenI25. As shown in Figs. 2 and 24, the lower end of the chute has arounded front edge I40 and its opposite sides I40 indented in a curvedcross-section and an upwardly flaring formation to facilitate themounting of satchel bottom type bags thereon by the customer. roundedleading edge tends to flatten the sides of the bag, while the indentedside portions of the chute accommodate the folds in the bag sides andgradually flare the bag sides as the bag is pushed on the chute end andthen left resting on the bottom of the shell 33.

The motor switch assembly I shown in Fig. 21 is a limit switch to startthe machine on the insertion of a coin and shut ofi the machine at thecompletion of the operating cycle. An adjustable operating bar I'II ispivotally connected to one side of the yoke I43 and is moved downwardlyas the popping basket is raised to its dumping position. The bar carriesa springpressed pawl I12 pivoted thereon which moves past a secondspring-pressed locking pawl I13 pivoted on the switch box. The pawl I13when in its locking position holds a flange I14 on a lever I15 pivotedon a bracket IISI from moving upwardly under the action of a spring I16.The lever I15 also has an insulated support I82 carrying one end of aspring contact I11 which is movable between upper and lower springcontacts I19 and I19. The lever I15 is pulled downwardly by the closingof a snap switch in the coin control mechanism momentarily exciting asolenoid I30, allowing the locking pawl I13 to engage the flange I14 andhold the contacts I11, I19 closed. As the basket is returned to itsinitial position at the end of the operating cycle, the bar I19 israised, causing the pawl I12 to engage and turn the pawl I13, asindicated in Fig. 21, to release the flange I14 and lever I15, whichunder the action of the spring I16, will move upwardly to open thecontacts I11, I19 and close the contacts I11, I18, cutting off the powerto the motor 05 and stopping the cycle.

The hollow thermal bulb H1 is immersed in the cooking oil pan andpositioned close to the surface of the oil, so as to transmit thetemperature of the oil in which the corn is popped as accurately as ispossible. The normal oil level is approximately one inch above the topsurface of the filler block H5, and the popping basket positioned tonormally have a depth of approxi- The Cir

mately one-quarter inch of oil therein in the lower bottom section inoperation. The thermal bulb and the flexible tube I connected theretoare filled with an expansion fluid and arranged to operate an on and offswitch I86 controlling the power supply to the heater I20.

In accordance with the invention, the thermostat system and motor speedare set to maintain a predetermined popping temperature and period. Forbest results a high grade hybrid type pop corn having a moisture contentnot less than 12% should be used. When a hydrogenated vegetablecompound, such as cocoanut or cottonseed oil, is used as the cookingoil, with the corn immersed therein, it has been discovered that apopping period of 55-65 seconds, and preferably approximately 60seconds, coupled with a cooking oil temperature in the range of 400-415F., and preferably 407-411 R, will give the maximum popping efficiency.The thermostat control is arranged to maintain the cooking oiltemperature within this 5 F. range. A lesser popping period with thistemperature range would not pop all the corn in the charge. Too high apopping temperature prevents the corn from exploding to its maximumvolume, causing it to be hard and tough, while a popping temperaturebelow this range results in a rate of heat input to the corn too slow tosecure the maximum popped volume.

The control switch box assembly I90, diagrammatically indicated in Fig.22 consists of a keyoperated main on-and-ofi control switch I9I, aterminal block I92, a single pole single throw relay I93, and a doublesingle pole single throw relay I94. When the machine is started at roomtemperature, a delay of 25-30 minutes is necessary before the oil isheated to the desired popping temperature range. During this heating-upperiod, it is essential that the coin mechanism does not accept anycoins. Since the required heating-up period will vary with the ambienttemperature, a definite period cannot be set, and the thermostaticcontrol of the heater I20 through the switch assembly I90 isadvantageously used for this purpose. As diagrammatically shown in Fig.23, when the machine is in the 01f position, the contacts I93 of therelay I93 are closed and the relay I94 has one pair of contacts I94 inthe thermostat circuit open and the other pair I94 in the coin controlcircuit closed. When the machine is started, the thermostat controlledcontacts are closed. Operation of the key switch I9I causes current toflow through the coil of the relay I93 and break the contacts, I93controlled thereby. However, before this circuit is broken, currentflows through the switch to the coil of the relay I94, causing thecontacts I94 to close and the contacts I94 to open. This coil is thenkept energized by the thermostat switch being in series therewith. Thusthe momentary energizing of the double S. P. S. T. coil I94 by the S. P.S. T. relay I93 puts the coil of the double S. P. S. T. re-

, lay in series with the thermostat. The relay I94 remains energizeduntil the thermostat switch I86 opens when the oil is heated to thedesired temperature, at which time the relay I94 returns to its normalposition. If the thermostat switch I86 should again close while the oilis at the proper temperature, the coil of the relay I94 will not beenergized since the contacts I93 of the relay I93 are open, as well asthe pair of contacts I94 of the relay I94 which are in series with thethermostat switch. This method of timing con- 9. trols exactly theheating-up. period of the, machine. during which time no current willbe; subplied to the coin mechanism which is therefore inoperative, and,will reject all coins. When the machine is up to its normal temperaturerange and the thermostat shuts off the flow of current to: the. heater,the relay I94v permits the coin mechanism to operate normally. Therelays. I93 and I94 thus function to insure that no coin. will beaccepted until the machine i in condition; to deliver popped corn to thecustomer. A secondary function of the relays I93, I94. is to keepinactive the. float control switch during the heating-up period. Thisprevents the solenoid valve I53 from opening and allowing cooking oil toenter thepan before the oil in the pan has expanded to its maximumvolume. This prevents the accumulation of excess oil in the pan during;the heating-up period, and also prohibits the solenoid valve. fromoverheating. If for any reason the relay I94 is thrown out during apopping cycle. the described sequence of operation will take. place. Themachine will stop until the thermostat has cut out, and thereupon therelay I94 will automatically reset, allowing the machine to complete thecycle.

The coin control mechanism 200, diagram.- matically indicated in Fig.22, is of any suitable gravitational selector type in which apredetermined coin will actuate a spring arm to close the electricalcircuit through the main motor switch relay solenoid I80 for asufficient time interval to permit the locking pawl I13 to swing intoposition to hold the contacts I11, I19 closed. The electrical systemincludes a fluorescent lamp MI in the top of the cabinet and knifeswitches 202 at convenient locations.

The operation of the machine will be apparent from the foregoingdescription of the operating parts and their functioning. With themachine in its normal operating condition, the insertion of apredetermined coin in the coin control mechanism starts the operatingcycle. The drive mechanism moves the loaded corn cup 88 in an are aboutthe pivot shaft 80, in the course of which movement the finger 8 opensthe door 85 in the oscillating popping basket. The continued movement ofthe basket causes the corn cup to engage the snubbing post I and dumpits load of corn into the oscillating basket. The cup then return-s toits loading position and the basket door closes automatically. Thedumped corn is distributed over the lower basket bottom perforatedsection and substantially covered by the layer of hot coo-king oiltherein maintained in the temperature range of 407-411 F. The preferredpopping period insures the popping of substantially every kernel. ofcorn, so that when the dumping cam is actuated to raise and tilt theoscillating popping basket, all of the corn will be discharged in apopped condition. The shut-off slide 56 insures that no raw corn isdischarged while the corn cup is moving away from and returning to itsloading position. The popping of the corn in the cooking oil results inthe absorption of approximately three-fourths of an ounce of oil in eachcharge popped. The loss of oil is automatically replaced by the floatcontrol 'activating the solenoid valve I53. As the basket lifts to dumpthe popped com, the liquid level will drop still farther due to the lossof the basket displacement, which will be restored to raise the oillevel when the basket returns. The float control system is set tocompensate for the displacement effect when the basket is returned. Thepopped corn cascades out of the popping basket through 10 the chute 31into. the. bag inserted by the cus tomer in the compartment 33. Theoperating cycle continues until the popping. basket returnsv to itsnormal horizontal position in the pan I I0. Atv this point themotorswitch is actuated to shut off the current supply to the motor andcomplete the cycle. The complete cycle requires seventyflve seconds witha popping period of sixty secends. the cycle to be repeated.

While. in accordance with the provisions of theheating said chamber, anelectrically operated coincontrolmechanism, and an electrical controlsystem. comprising a thermostatic switch responsive to the temperatureof said chamber for controlling, said heating; means, means. comprisinga relay arranged to be momentarily energized on the closing of saidthermostatic switch, and a second relay having one pair of contacts inseries with said thermostatic switch arranged to be closed onenergization of said first named relay and a second pair of contacts inseries with said coin control mechanism arranged to be opened onenergization of said first named relay.

2. In a corn popping machine, means forming a popping chamber adapted toreceive a supply of cooking oil and raw corn, electrical means forheating said chamber, an electrically operated coin control mechanism,and an electrical control system comprising a thermostatic switchresponsive to the temperature of said chamber for controlling saidheating means, means comprising a single pole single throw relayarranged to be momentarily energized on the closing of said thermostaticswitch, a double single pole single throw relay having One pair ofcontacts in series with said thermostatic switch arranged to be closedon energization of said first named relay and a second pair of contactsin series with said coin control mechanism arranged to be opened onenergization of said first named relay, and means for opening said firstpair of contacts and closing said second pair of contacts on the openingof said thermostatic switch.

3. In a corn popping machine, means forming a popping chamber adapted toreceive a supply of cooking oil and raw corn, means for supplying rawcorn to said popping chamber, valve controlled means for supplyingcooking oil to said popping chamber, electrical means for supplying heatto said popping chamber, an electrically operated coin control mechanismarranged to initiate a popping cycle on the insertion of a coin therein,and an electrical control system comprising a normally closedthermostatic switch responsive to the temperature in said poppingchamber and set to open when a predetermined operating temperature isreached, means for rendering said coin control mechanism operative whensaid predetermined operating temperature is reached, means formaintaining said cooking oil supply means in a closed position untilsaid The insertion of another coin will causepredetermined operatingtemperature is reached, and mechanical means for ending said poppingcycle after a predetermined time interval.

4. In a corn popping machine, means forming a popping chamber adapted toreceive a supply of cooking oil and raw corn, means for supplying rawcorn to said popping chamber, valve controlled means for supplyingcooking oil to said popping chamber, electrical means for supplying heatto said popping chamber, an electrically operated coin control mechanismarranged to initiate a popping cycle on the insertion of a coin therein,and an electrical control system comprising a thermostatic switchresponsive to the temperature in said popping chamber and arranged torender said heat supplying means in0perative when a predeterminedoperatin temper ature is reached, means for rendering said coin controlmechanism operative when said predetermined operating temperature isreached, means for maintaining said cooking oil supply means in a closedposition until said predetermined operating temperature is reached, andmechanical means for ending said popping cycle after a predeterminedtime interval.

JOHN LINDSTROM. BURGESS C. CASE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 226,373 Turner Apr. 6, 1880 Number 12 Name Date Dula May 24,1881 Detrick Mar. 7, 1893 Eckstein Nov. 17, 1908 Welsh Dec. 12, 1911Gronberg et a1. Apr. 9, 1912 Kohn Apr. 15, 1913 Simmons et al Feb. 24,1914 Saunders May 26, 1914 Harding -1 July 28, 1914 Le Claire Aug. 24,1926 Smith May 31, 1927 Howe Feb. 7, 1928 Taylor June 10,1930 Smith Dec.12, 1933 Blinn et a1 Jan. 2, 1934 Shroyer Feb. 5, 1935 Parks Jan. 14,1936 Pagendarm Mar. 17, 1936 Ehrgott Feb. 22, 1938 Obdyke Oct. 25, 1938Tuoyman Dec. 20, 1938 Delf Nov. 7, 1939 Coltman Mar. 12, 1940 Case Oct.8, 1940 Husk Nov. 19, 1940 Roth June 23, 1942 Stevenson Feb. 2, 1943Scott 1- Apr. 20, 1943

